Segmented Thermoelectric Oxide-Based Module for High-Temperature Waste Heat Harvesting
We report a high-performance thermoelectric (TE) oxide-based module using the segmentation of half-Heusler Ti_(0.3)Zr_(0.35)Hf_(0.35)CoSb_(0.8)Sn_(0.2) and misfit-layered cobaltite Ca_3Co_4O_(9+δ) as the p-leg and 2 % Al-doped ZnO as the n-leg. The maximum output power of a 4-couple segmented module at ΔT=700 K attains a value of approximately 6.5 kW m^(−2), which is three times higher than that of the best reported non-segmented oxide module. The TE properties of individual legs, as well as the interfacial contact resistances, were characterized as a function of temperature. Numerical modeling was used to predict the efficiency and to evaluate the influence of the electrical and thermal lo…
Influence of magnetization on the applied magnetic field in various AMR regenerators
International audience; The aim of this work is to assess the influence of a magnetic sample on the applied magnetic field inside the air gap of a magnetic circuit. Different magnetic sources including an electromagnet, a permanent magnet in a soft ferromagnetic toroidal yoke, as well as 2D and 3D Halbach cylinders are considered, using a numerical model. Gadolinium is chosen as magnetic material for the sample, due to its strong magnetocaloric properties and its wide use in magnetic refrigeration prototypes. We find that using uniform theoretical demagnetizing factors for cylinders or spheres results in a deviation of less than 2% in the calculation of internal magnetic fields at temperatu…